In a magnetic-recording disk of a hard-disk drive (HDD), a plurality of burst patterns having positions different from each other in the radial direction are formed in a self-servo writing (SSW) process. These burst patterns provide information for the location of a track by servo electronics of the HDD in the writing of data to the magnetic-recording disk. The HDD computes the deviation of the magnetic-recording head from the track and positions the magnetic-recording head based on the burst signals read out with the magnetic-recording head from the burst patterns. Under some circumstances, a plurality of burst patterns may be misaligned individually due to fluctuations in position of a magnetic-recording head during burst pattern writing. The effect of such misalignment is included in the computed deviation of the magnetic-recording head. For example, if a magnetic-recording head is positioned based on the deviation of the magnetic-recording head including the effect of such misalignment and new burst patterns are written to the magnetic-recording disk under such circumstances, misalignment may accumulate as further burst patterns are written as the self-servo writing (SSW) process proceeds.
Manufacturing and development engineers engaged in the manufacture and design of HDDs are interested in reducing the time to manufacture and in increasing the reliability of HDDs. Therefore, the attention of manufacturing and development engineers has been directed towards eliminating the effects of such misalignment.